Im not sure if this is a bug, but i figured it should be posted anyways

Look at my exp to the next level

(and yes i know im using a crappy machine to play on)

it probably just rounded to show you the exp when you had a decimal, but didn't round in the calculations, you probably needed less than one exp to level up

Probably just a rounding error. Floating point calculations in PHP are very strange.

One more attack would probably knock you to the next level.